Case Report
Amelogenesis Imperfecta with Taurodontism, Microdontia and Minor
Thalassemia: A Case Report
Fatemeh Mazhari1, Negar Mokhtari Amirmajdi2
1
Dental Material Research Center, Faculty of Dentistry, Mashhad University of Medical Sciences,
Mashhad, Iran
2
Department of Pediatric Dentistry, Facultyof Dentistry; Mashhad University of Medical Sciences,
Mashhad, Iran
Received 16 July 2013 and Accepted 8 November 2013
Abstract
Amelogenesis imperfecta is a group of genetic
disorders that affects both the morphology and quality
of tooth structure. Although the disease entity is
primarily associated with abnormalities of dental and
oral structures, it has been reported to be associated with
a few syndromes. A 9-year-old girl with minor
thalassemia referred to the Department of Pediatric
Dentistry of the Mashhad Faculty of Dentistry with a
complaint of sensitivity of first permanent molars.
Dental findings consisted of amelogenesis imperfecta,
microdontia, posterior cross bite and taurodontism. This
is the first report of thalassemia accompanied with
amelogenesis imperfecta. Although the patients often
are non-symptomatic, the trait can be passed on to a
child and if both parents carry the trait, the child could
develop a more severe form of the disease; therefore,
early diagnosis is important.
Key words: Amelogenesis imperfecta, Minor
thalassemia, Taurodontism, Microdontia.
Introduction
Amelogenesis imperfecta (AI) is a group of genetic
disorders that affects teeth. Depending on its type, both
the morphology and quality of tooth structure may be
altered. It can affect primary and/or permanent dentition
(1). The genetic pattern responsible for the disease may
be autosomal dominant, autosomal recessive, sex linked
or even sporadic (2).
The primary site of involvement in AIis the
dentition. However, other oral findings may also be
associated with the condition. These include dental and
skeletal open bite, pulpal calcification, dentin dysplasia,
taurodontism, crown and root resorption, unerupted
teeth, congenitally missing teeth, gingival hyperplasia
and follicular hyperplasia (3). Although the disease
entity is primarily associated with abnormalities of
dental and oral structures, it has been reported to be
associated with a few syndromes (4-6).
Thalassemia refers to genetic disorders in globin
chain production. In individuals with beta thalassemia,
there is either a complete absence of globin production
(thalassemia major) or a partial reduction in globin
production (thalassemia minor) (7).
This article presents a girl with hypoplastic AI who
also suffers from minor thalassemia and microdontia
accompanied with taurodontism and bilateral posterior
cross bite.
Case Report
--------------------------------------------------------Fatemeh Mazhari, Negar Mokhtari Amirmajdi.
Amelogenesis Imperfecta with Taurodontism, Microdontia
and Minor Thalassemia: a Case Report. J Dent Mater Tech
2014; 3(1): 37-41.
Mazhari et al.
A 9-year-old female patient referred to the
Department of Pediatric Dentistry of Mashhad Faculty
of Dentistry with a chief complaint of sensitivity of her
first permanent molars. She was first seen by a general
dental practitioner for restoration of her primary teeth.
Her physical examination was normal but her medical
history revealed minor thalassemia. The patient was
JDMT, Volume 3, Number 1, January 2014
37
treated symptomatically with folic acid and ferrous
sulfate supplements. She was born at full-term after a
normal pregnancy and uncomplicated delivery and her
post-natal period was uneventful. Moreover, she was of
normal development and intellect and there was no
consanguinity within the family. Family history showed
the same disease with same dental manifestations in one
of the older patient’s sisters. The patient’s mother was
examined and showed unaffected permanent dentitions.
Although the patient’s father refused an examination, he
had very small teeth without any tooth discoloration
according to his wife. The patient had two healthy older
brothers as well as another healthy older sister. The
patient lived in a non-fluoridated area and had never
taken fluoride supplements. In the intraoral
examination, soft tissue had a normal appearance. The
timing of tooth eruption and the emergence pattern
seemed to be within the normal range. The patient’s oral
hygiene was poor. Dental findings included
microdontia, enamel hypoplasia in all primary and
permanent teeth and posterior cross bite. There was no
space between teeth (Figs. 1 and 2).
The panoramic radiograph showed all permanent
teeth including molars. Taurodontism was observed in
four permanent first molars. There was also a thin layer
of enamel with normal density covering the dentin
(Fig.2).
Based on clinical and radiographic findings, a
diagnosis of hypoplastic AI was made and appropriate
treatment wasplanned based on the patient’s needs.
Treatment plan for this case consisted of oral hygiene
instructions, prophylaxis, topical fluoride therapy and
restorative treatment. Due to the sensitivity of the first
permanent molars and their susceptibility to further
structure loss caused by defective tooth texture and as
there was still a long period of growth remaining, all the
mandibular and maxillary first permanent molars were
treated by removing caries and restoring with temporary
full coverage stainless steel crowns (SSC) (3M
ESPE).Due to their small size, SSCs of the second
primary molars (no. 2) were used. Maxillary left
primary molars underwent pulpotomy and restored with
SSC. The patient refused treatment of her maxillary
right primary molars and the cross bite (Fig.3).
Figure 1. Intraoral photographs of the patient before treatment
a) Occlusal view of the mandibular arch, b) Occlusal view of the maxillary arch
38 JDMT, Volume 3, Number 1, January 2014
Amelogenesis Imperfecta
Figure 2. Dental anomalies present in the patient
a) Posterior cross bite b) Microdontia c) Taurodontism and enamel hypoplasia
Figure 3. Intraoral photographs of the patient after treatment (The mandibular primary molars had already been restored
by a general dental practitioner) a) Occlusal view of the mandibular arch, b) Occlusal view of the maxillary arch
Discussion
AI is a disease with hereditary origin that affects the
enamel of primary and permanent teeth. It is reported to
have an incidence of 1 in 718 to 1 in 14,000, depending
on the population studied (8).
It may cause different signs and symptoms
depending on the type of the disease. In the hypoplastic
type, the enamel is well-mineralized but its thickness
varies from thin and smooth to normal thickness with
grooves, furrows and/or pits. The enamel is hard but
because of its thinness it is more susceptible to
fracture.Radiographs exhibit thin radiodense enamel.
The hypocalcified type shows softened and easily
Mazhari et al.
detachable enamel. Radiographically, enamel has a
contrast similar to or even less than that of the dentin. In
the hypomaturation type, the affected teeth exhibit
enamel with a mottled, opaque white-brown-yellow
color, which is softer than normal but not as soft and
easily abraded as in the hypocalcified type. In
radiographs, the thickness of enamel is normal, but its
density is the same as that of the dentin (9).
In this case, as the enamel had normal hardness but
its thickness was less than normal and it was pitted, the
diagnosis of pitted hypoplastic type was made.
Association of AI with a group of dental anomalies
such as dental and skeletal open bite, pulpal
JDMT, Volume 3, Number 1, January 2014
39
calcification, dentin dysplasia, taurodontism, crown and
root resorption,unerupted teeth, congenitally missing
teeth, gingival hyperplasia and follicular hyperplasia has
been reported (3). The patient had a posterior cross bite
and taurodontism, but other mentioned anomalies were
not detected. Also, microdontia was observed. In some
types of AI the teeth with thin enamel are also small in
size and the interproximal contacts are open; however,
in this case there was a true microdontia and the teeth
appeared smaller than expected, maxillary laterals were
peg-shaped and the contacts were closed. The closed
contacts were probably due to a smaller than normal
maxilla, which also had resulted in a cross bite. For
restoration of the permanent teeth with SSC, even SSCs
no. 2 of second primary teeth was slightly loose for
them and required a greater amount of crimping to fit.
AI occasionally occurs in conjunction with
syndromes
such as
Kohlschutter
syndrome5,
Platyspondyly with AI (10), nephrocalcinosis (1), Jalili
syndrome (11), tricho-dento-osseous (2) and Heimler
syndrome (4). None of the signs and symptoms of the
mentioned syndromes were detected in the presented
case. However, medical history revealed presence of
beta-thalassemia minor. Based on genetic and clinical
features, thalassaemias are classified as homozygous,
heterozygous or compound heterozygous. Thalassemia
minor is the heterozygous form of the disease, which is
mild and usually asymptomatic; the only manifestation
is hypochromic microcytic anaemia. The homozygous
form of b-thalassemia named thalassemia major exhibits
the most severe clinical symptoms with marked
orofacial deformities (12). This patient received folic
acid and ferrous sulfate supplements. One of her older
sisters also suffered from thalassemia minor and AI.
However, the presence of AI was only reported by the
mother (according to her mother’s statement, the older
sister’s teeth had the same appearance as the patient).
The treatment plan for cases of AI is related to many
factors such as the severity of the disorder, the age of
the person, the socioeconomic status and the intraoral
condition. A conservative option is restoring with direct
composite that causes the least tissue loss due to
preparation methods. Another relatively conservative
approach is amalgam restoration which causes less
structure loss than full coverage restorations (13). In this
case, because of generalized pitting on the teeth surfaces
and teeth sensitivity, complete coverage was considered.
These teeth required full coverage with preformed
crowns until the end of growth when precision cast
crowns can be provided. Another consideration in
patients with AI is esthetics and the consequent
psychological complications (13). In this case,as the
anterior teeth were almost normal in color and shape
except for a few pits on labial surfaces, esthetics was
not a concern for the patient. The treatment plan focused
40 JDMT, Volume 3, Number 1, January 2014
on restoring the posterior primary and permanent teeth
for resolving the sensitivity and preventing tooth loss.
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Corresponding Author:
Negar Mokhtari
Faculty of Dentistry
Vakilabad Blvd, Mashhad, Iran
Tel: 0098-915-3169692
Fax: 0098-511-6090082
E-mail: [email protected]
Mazhari et al.
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